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34 Cytogenetic characteristics of human carcinoma cell lines derived from spontaneously and virally transformed human keratinocytes
37 33 ° Cl~OENEr]C AND MOLECULARMODIFICATIONS IN KiMSV TRANSFORM£1) AND REVKRTAEI"HUMAN 0STEOSARCOMA~FI ! Veeumt AM(1). Carloni G.{2).Rhim J(3) ~ d Az~trone B(4) (I) I N S ~ M UZ53, (4) U.265, Hop. P. Brousse 14 A v P Vaillam Couturier 94500 Villejuif.Irrsoce- (2) IRSC 8 rue G Moquet 94800 Villejuif ~ d CNR, Roms. Italy - (3) NIH, Bethesda, USA.
The human osteosarcome cell lJ~e Te85 acquires tumorigenic potential al'ter trsasformstion with the KiMSV. Stable non mmorilenic revorlants of this YHOS cell line have been obtained Therefore this cell system represents an ideal model for the study of the role of oncogenes in the scquisitlon of the tumorigenic potenl~J in human cells This study demonstrates, by hybridization, the integnU.ion of a single complete KLMSV proviJ-al DNA copy in the genome of the KHOScells sad its total sbeence in the HOS240S revertsnt. Cytogenetic analysis suglests thst loss of the integ~,ted provirus could be mediated by the partial or t o ~ loss of chromosomic msterial since the revertsat ceUs exhibit so increued chromosome fragility and • decreased chromosome modal number (47 out of 49) in comparison with KHOS cells The important chromosome rosrnmgemeets, inclu(Uag chromosomes where c-myc sad c-fes oncogeees Jure loc•ted (8q and 15q), msy generate the genetic instability underllying the full competence in the expression of the tumorigenic potential of the c-Ki-ras product.The increased genetic instabilitysad the higher sensitivity to viral (KilVISV) sad chemical (3MC) transformation of the HOS revertont cell strenghten the role of preexisting chromosome abnormalities in tumorigenicity.
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*CYTOGENETICCHARACTERISTICS OF HUMAN CARCINOMA CELL LINES DERIVED FROMSPONTANEOUSLY AND VIRALLY TRANSFORMEDHUMAN KERATINOCYTES. Dzarlieva-Petrusevska, R.T., Boukamp, P., and Fusenig, N.E. Division of Differentiation and Carcinogenesis in v i t r o , German Cancer Research Center, D-6900 Heidelberg, FRG. Several human keratinocyte cell lines, spontaneously and v i r a l l y (SV-40 and HPVI6) transformed were cytogenetically investigated and compared with two cell lines derived from human squamo~scell carcinomas of the skin. The primary cultures and early passages from carcinomas and in v i t r o transformed cell lines respectively contained an aneuploid (hypodiploid) chromosome complement, which shifted to a hypotetraploid stem line during c u l t i v a t i o n , concomitant with an improved growth capacity of the cells in v i t r o . All primary keratinocyte cultures and derived cell lines thereafter displayed individual and stable marker chromosomes in most of the metaphases, indicating a monoclonal origin of the tumor populations. Two major types of chromosomal alterations could be identified in G-banded metaphases: i. Translocations and isochromosomes due to the centromeric misdivision and 2. Long chromosomal structures formed from 2-3 attached chromosomes, due to the increased chromosomal stickiness. Whereas the f i r s t type of aberrations was characteristic for all cell lines, the second type was found prefere n t i a l l y in v i r a l l y transformed cell lines. The nonrandom involvement of specific chromosomes such as 3, 4, 7, 8, and 9 indicates the importance of these chromosomes for malignant transformation of human keratinocytes. Malignant conversion of SV-40 and spontaneously immortalized keratinocytes by transfection with activated c e l l u l a r ras oncogene was accompanied by emergence of new marker chromosomes. In agreement with our previous studies on transformed mouse keratinocyte cell lines, these data strongly support the hypothesis that specific chromosome changes leading to gene imbalance are causally related to early steps in the transformation of human and mouse keratinocytes.
The human osteosarcome cell lJ~e Te85 acquires tumorigenic potential al'ter trsasformstion with the KiMSV. Stable non mmorilenic revorlants of this YHOS cell line have been obtained Therefore this cell system represents an ideal model for the study of the role of oncogenes in the scquisitlon of the tumorigenic potenl~J in human cells This study demonstrates, by hybridization, the integnU.ion of a single complete KLMSV proviJ-al DNA copy in the genome of the KHOScells sad its total sbeence in the HOS240S revertsnt. Cytogenetic analysis suglests thst loss of the integ~,ted provirus could be mediated by the partial or t o ~ loss of chromosomic msterial since the revertsat ceUs exhibit so increued chromosome fragility and • decreased chromosome modal number (47 out of 49) in comparison with KHOS cells The important chromosome rosrnmgemeets, inclu(Uag chromosomes where c-myc sad c-fes oncogeees Jure loc•ted (8q and 15q), msy generate the genetic instability underllying the full competence in the expression of the tumorigenic potential of the c-Ki-ras product.The increased genetic instabilitysad the higher sensitivity to viral (KilVISV) sad chemical (3MC) transformation of the HOS revertont cell strenghten the role of preexisting chromosome abnormalities in tumorigenicity.
34
*CYTOGENETICCHARACTERISTICS OF HUMAN CARCINOMA CELL LINES DERIVED FROMSPONTANEOUSLY AND VIRALLY TRANSFORMEDHUMAN KERATINOCYTES. Dzarlieva-Petrusevska, R.T., Boukamp, P., and Fusenig, N.E. Division of Differentiation and Carcinogenesis in v i t r o , German Cancer Research Center, D-6900 Heidelberg, FRG. Several human keratinocyte cell lines, spontaneously and v i r a l l y (SV-40 and HPVI6) transformed were cytogenetically investigated and compared with two cell lines derived from human squamo~scell carcinomas of the skin. The primary cultures and early passages from carcinomas and in v i t r o transformed cell lines respectively contained an aneuploid (hypodiploid) chromosome complement, which shifted to a hypotetraploid stem line during c u l t i v a t i o n , concomitant with an improved growth capacity of the cells in v i t r o . All primary keratinocyte cultures and derived cell lines thereafter displayed individual and stable marker chromosomes in most of the metaphases, indicating a monoclonal origin of the tumor populations. Two major types of chromosomal alterations could be identified in G-banded metaphases: i. Translocations and isochromosomes due to the centromeric misdivision and 2. Long chromosomal structures formed from 2-3 attached chromosomes, due to the increased chromosomal stickiness. Whereas the f i r s t type of aberrations was characteristic for all cell lines, the second type was found prefere n t i a l l y in v i r a l l y transformed cell lines. The nonrandom involvement of specific chromosomes such as 3, 4, 7, 8, and 9 indicates the importance of these chromosomes for malignant transformation of human keratinocytes. Malignant conversion of SV-40 and spontaneously immortalized keratinocytes by transfection with activated c e l l u l a r ras oncogene was accompanied by emergence of new marker chromosomes. In agreement with our previous studies on transformed mouse keratinocyte cell lines, these data strongly support the hypothesis that specific chromosome changes leading to gene imbalance are causally related to early steps in the transformation of human and mouse keratinocytes.